1. Field of the Invention
The present invention relates to a desk device provided with a disk loading mechanism for transferring a disk when loading or unloading of a disk is performed.
2. Description of Related Art
FIG. 3 is a perspective view of a conventional disk device when its outside is viewed from above in a slanting direction. FIG. 4 is a perspective view of the disk device shown in FIG. 3 when its inside is viewed from below in a slanting direction. FIG. 5 is a perspective view to show the structure of a first selection lever of the disk device shown in FIG. 3 and FIG. 4. FIG. 6A to FIG. 6C are cross sectional views taken along a line VI—VI in FIG. 5 to show variations in a positional relationship between a chassis and the first selector lever and a second selector lever when a disk is normally unloaded. FIG. 7A and FIG. 7B are cross sectional views taken along a line VII—VII in FIG. 5 to show variations in the positional relationship between the chassis and the first selector lever and the second selector lever when a discrepancy of driving timing occurs. At this point, they are depicted as that, in FIG. 4 to FIG. 7B, the right side is a front side and the left side is a rear side. For this reason, an A direction shown by an arrow A, which will be described later, is a direction from the front side to the rear side and a B direction shown by an arrow B is a direction opposite thereto.
In the drawings, a reference numeral 1 denotes a box shaped chassis (case) to function as a package of the disk device and the chassis 1 has a slot 2 through which a disk (not shown) is loaded and unloaded, as shown in FIG. 3 and FIG. 4, and the slot 2 is provided with a shutter 3 which is turnably mounted thereon for opening or closing the slot 2a. In other words, the disk (not shown) can be loaded along the A direction and can be unloaded along the B direction. An angled protruding portion 1a, as shown in, for example, from FIG. 6A to FIG. 6C and the like, is formed at an edge portion of the slot 2 on inside of an upper bottom surface of the chassis 1 forming a part of the slot 2. Further, a driving motor 4 that provides a driving force for transferring the disk (not shown) is mounted at an edge portion of the slot 2 on an inside of one side of the chassis 1 forming a part of the slot 2. The driving motor 4, as shown in FIG. 4, is so arranged as to provide the first selector lever 6 and the second selector lever 7 with a driving force via a gear 5 and the like.
The first selector lever 6, as shown in FIG. 5 for example, has a rack 6a which is formed at a front position near the slot 2 in such a way that it can engage with the gear 5, an elastic body 8 which is mounted on a side away from the slot 2 and can abut against the protruding portion 1a of the chassis 1, a plate shaped support portion 6b which supports the elastic body 8 in a cantilever manner, a guide claw 6c which slides on a guide part 1b mounted on the upper bottom surface of the chassis 1, and a hook portion 6d which is formed at a rearmost portion and is connected to an urging member (not shown) for urging the first selector lever 6 in the A direction so as to return the first selector lever 6 to an original position in backside. The elastic body 8 is generally formed by a plate portion 8a which is integrated with the support portion 6b and has the nearly the same thickness as the support portion 6b and a rising portion 8b which rises from the plate portion 8a to the chassis 1 side. The elastic body 8 can bend with respect to the support portion 6b but it is not changed itself in volume. When the first selector lever 6 which is formed as described above is supplied with a driving force of the driving motor 4, it can reciprocate along the A direction and the B direction in a straight line region close to the protruding portion 1a of the chassis 1.
The second selector lever 7 is formed by, as shown in from FIG. 6A to FIG. 7B, a rising portion 7a which rises toward the first selector lever 6, a rack (not shown) that is formed at a front of the rising portion 7a and can engage with the gear 5, and a hook portion (not shown) that is formed at the rearmost portion and is coupled to an urging member (not shown) for always urging the second selector lever 7 in the A direction so as to return the second selector lever 7 to an original position in backside. When the second selector lever 7 is supplied with the driving force of the driving motor 4, it can reciprocate along the A direction and the B direction in a straight line region close to the first selector lever 6 at a driving start timing which is different from a driving start timing of the first selector lever 6.
In the chassis 1, a transfer rubber roller (not shown) that is rotated forward and backward to load and unload the disk (not shown) is arranged near the slot 2. Further, on the upper bottom surface of the chassis 1, as shown in FIG. 3, is arranged a sliding member 9 that when the disk (not shown) is loaded, is moved backward (in the A direction) to position the disk (not shown). In the chassis 1, as shown in FIG. 3, there is arranged a trigger member 10 that moves the first selector lever 6 in a manner operatively connected to the loading of the disk (not shown) to a position where the driving force of the driving motor 4 is transmitted to the first selector lever 6 thereby to switch a horizontal movement (in the A direction and in the B direction) of the disk (not shown) to a downward movement of the disk. At this point, the above respective portions and members construct a disk loading mechanism.
Next, an operation will be described.
First, when the disk (not shown) is inserted from the slot 2, the disk is pulled into the chassis 1 by the driving force of rotation in the normal direction of the transfer rubber roller (not shown). Next, one portion of a periphery of the disk (not shown) abuts against the sliding member 9 to retract the sliding member 9 thereby to position the disk (not shown). At this time, the trigger member 10 which is operatively connected to the retracting operation of the sliding member 9 pushes the first selector lever 6 toward the front side (in the B direction) to make the first selector lever 6 abut against the gear 5. Thus, the first selector lever 6 is supplied with the driving force of the driving motor 4 to start moving forward. When the first selector lever 6 moves forward to a predetermined position, the first selector lever 6 interferes with the second selector lever 7 and then the second selector lever 7 is pulled by a straight movement of the first selector lever 6 to be made abut against the gear 5. Thus, the second selector lever 7 is supplied with the driving force of the driving motor 4 to start moving forward, thereby moving to a predetermined final position.
Next, when the disk (not shown) is unloaded, the first selector lever 6 and the second selector lever 7 that are made to abut against the gear 5 by the driving force of the driving motor 4, are linearly moved backward (in the A direction) at the same time. When the second selector lever 7 is separated from the gear 5 at a predetermined position, the driving force supplied to the second selector lever 7 by the driving motor 4 is stopped and then the second selector lever 7 is pushed backward (in the A direction) to a normal position by the first selector lever 6 that continues being made to abut against the gear 5 and hence being driven by the driving motor 4 to a predetermined position. In other words, when attention is paid to variations in a relative positional relationship among the protruding portion 1a of the chassis 1, the elastic body 8 mounted on the first selector lever 6 and the rising portion 7a of the second selector lever 7, as shown in FIG. 6A, first, when the rising portion 7a of the second selector lever 7 is supplied with the driving force of the driving motor 4, it is moved in the A direction to a position directly below (proximity position) the protruding portion 1a of the chassis 1 and the second selector lever 7 is separated from the gear 5. Then, as shown in FIG. 6B, the rising portion 8b of the elastic body 8 of the first selector lever 6 that continues to be supplied with the driving force of the driving motor 4, is made to abut against the protruding portion 1a of the chassis 1 thereby to be pressed and sunk downward. By this downward movement of the elastic body 8, the plate portion 8a of the elastic body 8 is made to abut against a side surface of the rising portion 7a of the second selector lever 7. Thus, as shown in FIG. 6C, along with movement in the A direction of the first selector lever 6 that continues to be supplied with the driving force of the driving motor 4, the second selector lever 7 is returned back in the A direction to the normal position.
However, because the conventional disk device has a structure as described above, it presents the following problem. That is to say, if the first selector lever 6 and the second selector lever 7 are moved and made to abut against the gear 5, for example, by a shock or the like in a state where the disk (not shown) is not loaded in the disk device, the first selector lever 6 and the second selector lever 7 start to be linearly moved at the same time by the gear 5 when a next disk loading operation is performed, that is, a discrepancy of driving timing (hereinafter also referred to as discrepancy of mode) occurs. At this time, the first selector lever 6 is not moved to a position where the disk is completely loaded and then is changed to an unloading operation. At this point, as shown in FIG. 7A, the elastic body 8 of the first selector lever 6 and the rising portion 7a of the second selector lever 7 will pass under the protruding portion 1a of the chassis 1 at the same time, so that, as shown in FIG. 7B, the plate portion Ba of the elastic body 8 of the first selector lever 6 which is pressed downward by the protruding portion 1a of the chassis 1, interferes with an upper surface of the rising portion 7a of the second selector lever 7. For this reason, both of the first selector lever 6 and the second selector lever 7 are in a state where they are made to abut against the gear 5, thereby moving both selector levers 6, 7 presents a problem of bringing both the selector levers 6, 7 into a locking state.